FIGS. 13A through 13C are partial cross-sectional views of a one-way clutch without dampening. The following should be viewed in light of FIGS. 13A through 13C. One-way clutches are used in stators to rotationally disengage the blades of the stator from the shaft of the stator during a free-wheel mode and to rotationally lock the blades and the stator shaft during a locked mode. During the transition from the free-wheel mode to the locked mode, the stator changes from spinning (free-wheeling) to carrying torque. To lock the clutch, various components of the clutch are brought into contact. The impact associated with the contact can generate undesirable noise and vibration.
For example, in FIG. 13A, plate 802 is rotatable and includes openings 804. Plate 806 is rotatably fixed and includes protrusions 808. Plate 806 is urged in direction 809 by resilient means (not shown). In FIG. 13A, the clutch is in a free-wheel mode (plate 802 rotates in direction 810). Segments 816 of plate 802 engage segments 814 and plate 812 also rotates in direction 810. Intermediate plate 812 slides over plate 806 and protrusions 808 such that protrusions 808 do not engage openings 804.
In FIG. 13B, the clutch switches to a locking mode and plate 802 rotates in direction 818. As this rotation occurs, openings 820 in plate 812 begin to align with openings 804. Plate 812 rotates such that openings 804 and 820 align sufficiently to enable protrusions 808 to drop into openings 804. As the protrusions drop into openings 804, segments 814 engage the protrusions. In FIG. 13C, segments 816 rotate into segments 814 to lockingly engage plates 802 and 806. However, as segments 816 push into segments 814, the inertia or energy associated with plates 802 and 812 causes an undesirable vibration and noise. That is, there is little or no braking of the movement of plates 802 and 812 into plate 806.
The magnitude of the energy, and hence the magnitude of the noise and vibration, is related to the lash associated with the movement of the components during the transition. It is known to include counteracting components within the clutch to minimize the lash. These components entail a high degree of precision to function properly. Unfortunately, this degree of precision can be much greater than or even incompatible with the precision associated with the remaining components in the clutch. For example, stamped components in a clutch can greatly reduce the cost and complexity of the clutch. However, it may be difficult or even impossible to incorporate the counteracting components noted above using stamped components.
Thus, there is a long-felt need for a means of reducing noise and vibration in a one-way stator clutch while simultaneously enabling the use of more cost-effective processes, configurations, and components.